Antibody Cocktails at Low Doses Could Be More Effective at Treating COVID-19, Finds Study

Pairs of antibodies may be more effective than single antibodies at preventing and treating COVID-19, according to a new study.

Researchers at the University of North Carolina at Chapel Hill (Chapel Hill, NC, USA) and The Rockefeller University (New York, NY, USA) who conducted the study have also suggested that in addition to blocking SARS-CoV-2's entry into cells, the antibodies may combat the virus by enlisting various types of white blood cells to fight the infection.

Human antibodies that neutralize SARS-CoV-2 hold great potential for preventing and treating COVID-19, and researchers have identified several potent antibodies that bind to the spike protein on the virus's surface, thereby preventing it from mediating the virus's entry into cells. The researchers tested the ability of several human antibodies to prevent SARS-CoV-2 infection in mice or hamsters. Surprisingly, they found that certain antibodies were more potent than expected. Some antibodies that were relatively poor at blocking viral entry into cultured cells were much more effective at preventing SARS-CoV-2 infection in rodents. The researchers determined that this was partly because, in addition to blocking viral entry, the antibodies can activate various types of white blood cells. These "antibody effector functions" help the immune system target the virus and/or virally infected cells.

The researchers also found that antibodies may be even more effective when used in combination with each other. Pairs of antibodies that target slightly different parts of the viral spike protein could successfully prevent or treat SARS-CoV-2 infection in mice and hamsters at much lower doses than single-antibody treatments. This is a particularly attractive approach because targeting multiple parts of the spike protein reduces the chance of the virus mutating and becoming resistant to antibody treatments.

"Some antibody combinations can be effective for prevention and early therapy of SARS-CoV-2 even at relatively low doses," said Timothy P. Sheahan, an assistant professor at the Gillings School of Public Health at the University of North Carolina at Chapel Hill. "Overall, our data support the idea that specific combinations of antibodies with the ability to activate immune cells should be developed for optimal protection and therapy against SARS-CoV-2."

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University of North Carolina at Chapel Hill
The Rockefeller University